you don't want to do it like that, do it like this

Good advice is hard to come by and we do have a minor technical problem which needs a bit of brain work. Putting in the foundations is not going to involve levelling four corners and triangulating between the rest of them as on a conventional rectangular build as we have two dodecahedra with twelve sides and 30° between each face and a linking corridor - the only bit with 90° corners. Yes, I know we have brought it on ourselves. The blockwork on each 30° has to be within 10mm across a diameter of 12 metres and 9 metres respectively for the two pods for the sole plate of the SIPS kit. I was thinking of trimming the 140mm blocks off at the required angles for butting alternating courses - the other being overlapped and using a template pivoted off the centre point to get it really accurate and then building opposite facets (which are parallel) first for alignment and working back off them. Now this is what I wake up thinking about at 3.a.m., or 4 a.m. or whenever.... Our founds are going to be 140mm block for the frames to sit on with another course outside for the stone walls - and where the depth of fill is over a certain amount to bolster the wall, though this bit is not a problem in terms of building. Today Lindsay suggested making up a standard formwork and concreting all the 30° corners filling in the runs with blocks. It sounds good and quite possibly more buildable in practice. We'd need to put in steel bar - again fairly easy. We are mixing everything in 1/10th cube lots and cannot get ready mix on site so small batches for each corner has its merits - prob. need about 5 courses high block equivalent....Does it make sense ?